| 摘要 |
A polishing head is suitable for polishing a semiconductor wafer and for providing endpoint detection during chemical-mechanical polishing. The head features an arrangement of patterned active actuators and load cells above the wafer to fully control the wafer surface profile changes and provide endpoint detection during the polishing processes. Each active actuator applies pressure according to the local coated thin film thickness on the wafer and relative velocity between the wafer and polishing pad. The load cell senses the actual force pressing on the wafer and feeds the information back to the actuator to adjust the force to a preset value, The planar endpoint is detected by sensing a change in friction force between different thin film material on the wafer. The change in friction force is detected by the load cell and a signal is produced to adjust or stop the process.
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